I don't initiate any touching; I prefer to keep my distance. If they see me I will say hi, if they don't, I will avoid eye contact so they don't see me. If they initiate a handshake, hug, or kiss, I will just grin and bear it.
I think it all depends on who the person is. Some I will shake hands with; some I will hug and/or kiss. Today I went in for the kiss. In my culture, we do two kisses, and, for some reason, I automatically went in for the two with this woman I had met for the second time. Lovely woman! The funny thing was that she went in for three as that is what is done where she comes from. It was lovely because it made me feel very welcome. :-D
There's usually hugging . . everybody I know seems to hug. (In England as a kid it seemed all the adults hugged.) Sometimes there's kissing and then I have to count as I have friends who are German, French, Swiss etc. LOL. Don't lose count - it makes a mess :-)))
It would depend on who it is. Are they a close friend or an acquaintance. Usually we hug or kiss, but sometimes we do neither, we just talk. I never shake hands with friends or acquaintances. Bit too formal for me.